The background of the present invention is set forth eloquently in an article written by Martha K. Kwitny, herself a kidney patient and a Deputy Attorney General in the Antitrust Section of the New Jersey Attorney General's office, entitled: "Alternatives to Kidney Dialysis," which appeared on the editorial page of the Wall Street Journal, Mar. 1, 1978. The Kwitny article is incorporated herein by reference and a copy is attached as Exhibit "A" to this application.
Supplementing the agonizing human problems discussed in that article, as caused by prior art dialyzing systems, it is noted that a grown human has a blood volume of approximately 5,000 to 6,000 milli liters (ml-approximately 5 to 6 quarts). Some of the numerous technical problems with the large dialyzer systems as discussed in the Kwitny article in use today are as follows:
1. From approximately 300 ml to 800 ml of the patient's blood is withdrawn from the patient and flows in extracorporeal relationship through such large, bulky, expensive dialyzer systems of the prior art. In other words, from approximately 5% to 16% (or even more for a smaller person) of the patient's total blood volume is flowing outside of the patient's body, which is inherently a risky arrangement.
2. Withdrawing such a high percentage of the patient's total blood volume often leads to cramps, such as leg cramps, and can cause shock to occur in the patient.
3. If clotting should occur in the dialyzer system, then the patient must be disconnected, and immediately there is a loss of from 300 ml to 800 ml of blood, which is left clotted in the dialyzer.
4. A pump is used to circulate the extracorporeal blood under pumping pressure through such a large dialyzer system. Such pumps routinely damage or break blood cells, which is deleterious to the patient.
5. The pumping pressure (which is considerably higher than normal blood pressure) places stress on the semipermeable membrane of the prior art dialyzer system and increases the risk of membrane rupture, which occurs from time to time in such prior art dialyzer systems.
6. The large, bulky, expensive prior art dialyzer systems often have a large tank, for holding the dialysate brine solution, such as one containing 120 gallons for simultaneous use by several patients in common. It is not feasible to sterilize such a large tank of brine solution, and there are organisms called pseudomonas which can live in such extremely salty solutions. Consequently, a patient using such a prior art system is continually at risk of getting a serious pseudomonal septicemia (blood infection from pseudomonas) in event of membrane rupture allowing dialysate solution to leak into the patient's blood. These pseudomonas organisms are very difficult to kill in a septicemia because they are almost insensitive to the various known antibiotics.
7. A number of patients are all connected to the same overall dialyzer system which is an inherently risky situation.
8. The flow rate in such large prior art dialyzer systems in handling approximately 300 ml to 800 ml of blood is such that it requires about twenty minutes for this quantity of blood to pass through the system and to return to the patient's body. In other words, this means that there is about one "pass-through" of handled blood in twenty minutes, which only amounts to three pass-throughs of handled blood per hour.
9. Complex monitoring equipment is needed, including that to make certain that the pumping pressure does not become too high and to determined whenever a membrane ruptures.
10. Since the patient is connected to an expensive prior art dialyzer system at a doctor's office or at a medical service center, there is inherent time and economic pressure, which may dictate that the patient's blood must be dialyzed at a faster rate than that which is optimum for the particular patient. Various patients often have markedly different optimum dialyzing rates due to their differing conditions. Consequently, use of the prior art dialyzer systems tends to be a harshly brutal experience for many patients as reflected by Martha K. Kwitny's writing, discussed above.
It is among the objects of the present invention to overcome these problems of the prior art.